There is an urgent need for an inexpensive coolant-heated diesel fuel warmer which is light in weight, has a high efficiency, which effectively precludes fuel contamination, and is of small compass so that it can be readily mounted beneath the hood of the vehicle. A primary requirement is that it must somehow preclude coolant from being drawn into the fuel line, which is conventionally under fairly high negative pressure. If this occurs, the fuel injector will burn out and fail, the cylinder walls will be scored, and other consequent damage will result, requiring repairs totalling several thousands of dollars.
Various types of fuel warmers have recently been designed in an attempt to prevent such fuel contamination, but most of these involve the use of relatively bulky chambers. Such chambers permit areas of fuel stagnation to develop therewithin and are also of undesirable size and weight. Modern vehicles are designed to provide very little room under the hood for any structure other than that provided by the original equipment manufacturer, and hence it is important that such a fuel warmer be of minimum size. Those presently on the market approximate eight inches in length and at least two inches in diameter.
Further disadvantages of the chamber type fuel warmers are that the mass thereof is excessive and they cannot be oriented in all directions, as desired. The weight of such a fuel warmer, combined with the weight of the relatively large quantity of fluid therein, provides more momentum than desirable in the event of a crash of the vehicle, frequently resulting in rupture of the fuel line and/or the coolant line. My invention is directed toward obviating each of these now-existent problems.